60 frames with half the detail is still 60 different pictures. 30 fps will produce noticeable stepping on camera pans or smearing when actors move. 60i (assuming it really comes from 60 different frames and not 30 frames shown twice) should render smoother camera pans and maintain better definition during movement.

The reason some people like low frame rates is because feature films use 24. This was always compromise between rendering movement and the cost of film. But some people now prefer the 24fps look because it is associated with the high budgets, high production values and good lighting of feature films, but I would always rather have 50 or 60 fps even if they are interlaced.